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Mars_B4_Moon

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Registered: 2006-03-23

Posts: 9,776

Re: Extrasolar Habitable Planets

JWST Might Have Imaged a Hycean World for the First Time, With a Hydrogen-Rich Atmosphere and a Deep Planet-Wide Water Ocean

https://www.universetoday.com/163123/jw … ter-ocean/

Despite its great oceans, Earth is not really an ocean world. It has less water than icy moons such as Europa and Enceladus, a relatively thin nitrogen-rich atmosphere, and vast continents that rise above sea level. A true ocean world would have no continents, a warm sea hundreds of kilometers deep, and a thick hydrogen and water-rich atmosphere. They are known as hydrogen-ocean planets or hycean worlds. While we’ve long thought they exist, the James Webb Space Telescope may now have found one.

Hycean planets are thought to be common in the super-Earth range of mass and size. Super-Earths are often found orbiting red dwarf stars, which are known to have tremendous solar flares. A planet orbiting in a red dwarf’s warm habitable zone risks being stripped of its atmosphere. With a stronger surface gravity than Earth, hycean planets could keep hold of much of their initial atmosphere, which is likely hydrogen and helium, and with a geologically active interior, they could have a strong magnetic field to protect against x-ray radiation and flares. With a mineral-rich warm ocean and thermal ocean vents that could provide the organic building block for life, hycean planets are excellent candidates for alien life. If they exist.

New observations by JWST suggest that they do. The planet in question is K2-18 b. It has a mass nearly 9 times that of Earth, and a radius almost 3 times that of Earth. Its orbit is in the habitable zone of a red dwarf star just 120 light-years from Earth.

Calliban

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From: Northern England, UK

Registered: 2019-08-18

Posts: 3,797

Re: Extrasolar Habitable Planets

Unlikely to be habitable, but interesting for their sheer oddity.  This star is orbited by two planets that are rocky, but have masses 87 and 64 times that of Earth.
https://en.m.wikipedia.org/wiki/Kepler-277

The larger of the two is almost as heavy as Saturn, but appears to be made of solid rock!  Due to the high gravitational compression, they are both denser than Earth.  We can only speculate about surface conditions.  But it is hard to imagine anything like complex life or a civilisation evolving under such crushing gravity.  Presumably, were such life to evolve, it would be trapped on the planet by its heavy gravity.  Surface gravity would be 10x that of Earth.  One wonders what other oddities await us in this universe.  Just how big can a rocky planet get?  A few larger solid objects have been discovered.  One solid carbon planet with a mass greater than Jupiter.  But that appears to be a stellar remnant.

Last edited by Calliban (2023-09-14 17:44:40)

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"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."

Steve Stewart

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From: Kansas City (USA)

Registered: 2019-09-21

Posts: 161

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Re: Extrasolar Habitable Planets

Here's a short video clip from "Astro Alexandra" about the planet K2 18 b.
The JWST might have detected DMS, which on Earth is only produced by life.

https://www.youtube.com/watch?v=3folN2XokZg

Last edited by Steve Stewart (2023-09-15 08:26:45)

Mars_B4_Moon

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Registered: 2006-03-23

Posts: 9,776

Re: Extrasolar Habitable Planets

K2-18b maybe now classed by media as a Super Earth which might have life

Some other Exoplanet news

'Exoplanet with a large iron core adds to puzzle of how planets form'
https://www.spacedaily.com/reports/Exop … m_999.html

Last edited by Mars_B4_Moon (2023-09-18 05:03:35)

Calliban

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From: Northern England, UK

Registered: 2019-08-18

Posts: 3,797

Re: Extrasolar Habitable Planets

Tau Ceti appears to have a Kuiper Belt containing about 10x the mass of all asteroids and comets orbiting our Sun.
https://en.m.wikipedia.org/wiki/Tau_Ceti

This makes Tau Ceti a poor candidate for evolution of complex life.  But it may be a good candidate for eventual human colonisation.  All of those comets and asteroids would be building materials for a space faring civilisation.

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"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."

Mars_B4_Moon

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Registered: 2006-03-23

Posts: 9,776

Re: Extrasolar Habitable Planets

A New Planet-Hunting Instrument Has Been Installed on the Very Large Telescope

https://www.universetoday.com/163384/a- … telescope/

Void

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Registered: 2011-12-29

Posts: 7,831

Re: Extrasolar Habitable Planets

I have to do a little work to get this article on topic, and I will: https://www.msn.com/en-us/news/technolo … =6#image=1  Quote:

NASA's James Webb Space Telescope (JWST) has made a groundbreaking discovery of Jupiter-sized "planets" freely floating in space, unattached to any stars. These intriguing objects, observed within the Orion Nebula, are referred to as Jupiter Mass Binary Objects, or "JuMBOs" for short.

If these binary worlds have worlds orbiting them then some pretty weird methods of a habitable planet can happen.  Mar to Super Earth size, may have their own radioactive decay, but there could be tidal heating for them.

And if these gas giants have magnetic fields, then radiation belts.  We might ask what would happen if Venus orbited in the radiation belts of Venus?  Well, this Venus might have a Hydrogen envelope over its atmosphere.  The radiation might actually synthesize chemicals for life to live on.

Anyway, it could be that some of these may be hiding near our Solar System?

Many more questions than answers.

Done

Last edited by Void (2023-10-03 19:06:27)

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Mars_B4_Moon

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Registered: 2006-03-23

Posts: 9,776

Re: Extrasolar Habitable Planets

Large pairs of Jupiter sized planets getting flung around out there seems a little scary

Mars_B4_Moon

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Registered: 2006-03-23

Posts: 9,776

Re: Extrasolar Habitable Planets

Hubble, Webb Data Hint at Ocean Worlds

https://skyandtelescope.org/astronomy-n … an-worlds/

Mars_B4_Moon

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Registered: 2006-03-23

Posts: 9,776

Re: Extrasolar Habitable Planets

The Combination of Oxygen and Methane Could Reveal the Presence of Life on Another World

https://www.universetoday.com/163709/th … her-world/

Mars_B4_Moon

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Registered: 2006-03-23

Posts: 9,776

Re: Extrasolar Habitable Planets

Do Red Dwarfs or Sunlike Stars Have More Earth-Sized Worlds?
https://www.universetoday.com/163787/do … ed-worlds/

Earth is our only example of a habitable planet, so it makes sense to search for Earth-size worlds when we’re hunting for potentially-habitable exoplanets. When astronomers found seven of them orbiting a red dwarf star in the TRAPPIST-1 system, people wondered if Earth-size planets are more common around red dwarfs than Sun-like stars.

Mars_B4_Moon

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Registered: 2006-03-23

Posts: 9,776

Re: Extrasolar Habitable Planets

JWST Sees Four Exoplanets in a Single System
https://www.universetoday.com/163931/jw … le-system/

When the JWST activated its penetrating infrared eyes in July 2022, it faced a massive wish-list of targets compiled by an eager international astronomy community. Distant, early galaxies, nascent planets forming in dusty disks, and the end of the Universe’s dark ages and its first light were on the list. But exoplanets were also on the list, and there were thousands of them beckoning to be studied.

But one distant solar system stood out: HR 8799, a system about 133 light-years away.

Mars_B4_Moon

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Registered: 2006-03-23

Posts: 9,776

Re: Extrasolar Habitable Planets

Rogues’ Gallery Comes in Pairs - A new trove of free-floating planets, smaller and paired up more than expected, challenges stellar and planet formation models

https://eos.org/articles/rogues-gallery-comes-in-pairs

Mars_B4_Moon

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Registered: 2006-03-23

Posts: 9,776

Re: Extrasolar Habitable Planets

5,535!
https://twitter.com/NASAExoplanets/stat … 1358900241
That's how many planets we've confirmed beyond our solar system. Some have clouds made of tiny particles of rock, iron or the material that forms jewels like rubies and sapphires. Each one is a wonder.

Void

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Registered: 2011-12-29

Posts: 7,831

Re: Extrasolar Habitable Planets

Well, I have always thought that cold terrestrials could be of some interest: https://www.msn.com/en-us/news/technolo … 3d332&ei=2
Quote:

Habitable zone where we may find alien life is expanded by new study
Story by Andrei Ionescu  •
5d

In our solar system, if a terrestrial had been pushed into an orbit like that of Saturn, it should still allow for a Nitrogen Gas atmosphere.

If it were a rocky planet with ice sheets, it might have plate tectonics.

If it did, it might have a magnetic field, or be protected by other planets magnetic field, (Just Maybe).

Being farther away from a Red Dwarf star, it might hold an atmosphere.

And it might even spin.

So, if humans can ever do interstellar travel, we might want to find such worlds.

I would think it might not be impossible for such a world to have a small amount of open water, if geothermal actions were sufficient.

Done

Last edited by Void (2023-11-17 13:26:08)

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Mars_B4_Moon

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Registered: 2006-03-23

Posts: 9,776

Re: Extrasolar Habitable Planets

JWST Peers into the Atmosphere of a Puffy, Fluffy Planet!

https://www.universetoday.com/164387/jw … fy-planet/

Mars_B4_Moon

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Registered: 2006-03-23

Posts: 9,776

Re: Extrasolar Habitable Planets

Deformable Mirrors in Space: Key Technology to Directly Image Earth Twins
https://www.spacedaily.com/reports/Defo … s_999.html

Deformable mirrors will enable future space coronagraphs to achieve this level of control. These devices will be demonstrated in space on a coronagraph technology demonstration instrument on NASA's Roman Space Telescope, which will launch by May 2027.

Deformable Mirrors (DM) are devices that can adjust the optical path of incoming light by changing the shape of a reflective mirror using precisely controlled piston-like actuators. By adjusting the shape of the mirror, it is possible to correct the wavefront that is perturbated by optical aberrations upstream and downstream of the DM. These aberrations can be caused by external perturbations, like atmospheric turbulence, or by optical misalignments or defects internal to the telescope.

DM technology originated to enable adaptive optics (AO) in ground-based telescopes, where the primary goal is to correct the aberrations caused by atmospheric turbulence. The main characteristics of a DM are: 1) the number of actuators, which is proportional to the correctable field of view; 2) the actuators' maximum stroke - i.e., how far they can move; 3) the DM speed, or time required to modify the DM surface; 4) the surface height resolution that defines the smallest wavefront control step, and (5) the stability of the DM surface.

Ground-based deformable mirrors have set the state-of-the-art in performance, but to lay the groundwork to eventually achieve ambitious goals like the Habitable Worlds Observatory, further development of DMs for use in space is underway.

For a space telescope, DMs do not need to correct for the atmosphere, but instead must correct the very small optical perturbations that slowly occur as the space telescope and instrument heat up and cool down in orbit. Contrast goals (the brightness difference between the planet and the star) for DMs in space are on the order of 10-10 which is 1000 times deeper than the contrast goals of ground-based counterparts. For space applications total stroke requirements are usually less than a micrometer; however, DM surface height resolution of ~10 pm and DM surface stability of ~10 pm/hour are the key and driving requirements.

Another key aspect is the increased number of actuators needed for both space- and ground-based applications. Each actuator requires a high voltage connection (on the order of 100V) and fabricating a large number of connections creates an additional challenge.

Mars_B4_Moon

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Registered: 2006-03-23

Posts: 9,776

Re: Extrasolar Habitable Planets

Where are All the Double Planets?

https://www.universetoday.com/164456/wh … e-planets/

Mars_B4_Moon

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Registered: 2006-03-23

Posts: 9,776

Re: Extrasolar Habitable Planets

Alien haze, cooked in a lab, clears view to distant water worlds
https://www.spacedaily.com/reports/Alie … s_999.html
Scientists have simulated conditions that allow hazy skies to form in water-rich exoplanets

Void

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Registered: 2011-12-29

Posts: 7,831

Re: Extrasolar Habitable Planets

Some of you may like this video: https://www.youtube.com/watch?v=lhDu6EjZqjg
Quote:

2 Trillion Planets Have Gone Missing and We Don't Know Why

Thoughty2
5.31M subscribers

I like the materials.

But I would like to add something.

1) While in the early universe, if a big bang was the origin, the temperature would have allowed liquid open water on many rogue planets, even if without a special condition as he mentioned.

2) So, presuming enough distribution of needed chemicals, at least in some areas, a multiple of incubators would have existed parallel in time.

3) He did not mention actual radiolysis origination of chemicals in wet sediments, although he does mention chemosynthesis from hydrothermal vents.

Here is an article that seems to support #3: https://www.usgs.gov/publications/contr … %20surface.

And I would make note my opinion that if H2 is being produced from water by radiolysis, then also oxygen is being produced.  If organism's bond to Carbon, then it could be that some extra Oxygen would be left over.  Maybe, but of course that might bond to rocks.

But maybe free Oxygen without Photosynthesis.

So, maybe some complex organisms.

Done

Last edited by Void (2023-12-11 22:32:15)

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Mars_B4_Moon

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Registered: 2006-03-23

Posts: 9,776

Re: Extrasolar Habitable Planets

Exomoons Defy Discovery

https://www.universetoday.com/164738/ex … discovery/

Mars_B4_Moon

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Registered: 2006-03-23

Posts: 9,776

Re: Extrasolar Habitable Planets

UBC graduate discovers more than 3,000 likely planets
https://www.cbc.ca/player/play/2294602307565

Astronomer Michelle Kunimoto explains how she uses data from NASA's transiting exoplanet survey satellite to detect likely planets orbiting distant stars many light years away. The 30-year-old University of B.C. graduate has discovered more than 3,000 planetary candidates, and is set to join her alma mater's astronomy faculty in 2024.

Mars_B4_Moon

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Posts: 9,776

Re: Extrasolar Habitable Planets

The Atmosphere of an Exoplanet Reveals Secrets About Its Surface

https://www.universetoday.com/164971/th … s-surface/

Mars_B4_Moon

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Registered: 2006-03-23

Posts: 9,776

Re: Extrasolar Habitable Planets

Want to Find Life? See What's Missing in an Atmosphere

https://www.universetoday.com/165067/wa … tmosphere/

Mars_B4_Moon

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Registered: 2006-03-23

Posts: 9,776

Re: Extrasolar Habitable Planets

GJ 367b is Another Dead World Orbiting a Red Dwarf

https://www.universetoday.com/165065/gj … red-dwarf/

Red dwarf exoplanet habitability is a hot topic in space science. These small dim stars host lots of exoplanets, including small rocky ones the size of Earth. But the little stars emit extremely powerful flares that can damage and strip away atmospheres.
If we’re ever going to understand red dwarf habitability, we need to understand the atmospheres of the exoplanets that orbit them.